Major changes in 2012 Uniform Plumbing Code include non-potable rainwater applications

March 27, 2012 |
Lynne Simnick

The 2012 Uniform Plumbing Code includes significant changes, with new provisions for alternative water sources for non-potable applications, rainwater catchment systems, plumbing facilities, and joining methods for water supply and drainage piping. This edition has improved layout design features, innovative efficiency standards, and upgraded sustainable practices.

New standards include water consumption requirements for a maximum flow rate in accordance with ASME A112.18.1/CSA B125.1. An added provision reduces scalding risk by requiring individual and tub-shower control valves to provide protection based on the flow rate of the shower head. Other changes include required waste outlet sizing, referencing material, and sizing provisions, and the removal of the requirement for a finished dam curb or threshold to aid the aging population. 

The code now offers various joining methods and connections to aid the end-user in identifying correct methods based on piping material. Reclaimed water provisions to on-site, non-potable water systems include gray water and other sources used for on-site applications. They are unique by installation through prepackaged or engineered systems that are listed, and labeled for the intended application.

A new chapter is dedicated to non-potable rainwater catchment systems. It covers irrigation, toilet and urinal flushing with proper treatment; provisions where permits are required; maintenance of alternate water sources; and minimum water quality.

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NOTE:This information is the opinion of the author/blogger and not the official position of IAPMO.

Lynne Simnick | Codes and Standards

Lynne Simnick is the Director of Code Development for the International Association of Plumbing and Mechanical Officials (IAPMO) and is responsible for the supervision and oversight of the creation and maintenance of all IAPMO codes and code supporting documents. Ms. Simnick has more than twenty-eight years experience in the plumbing industry including code development, education and training, plan review and evaluation services. Prior to joining IAPMO, Simnick worked as technical staff in engineering services, educator, inspector and plumber. She has a Bachelors of Science Degree in Education and Mechanical Engineering Technology. Simnick has authored many technical articles, participated in numerous standards committees with an expertise in code and standards development.

Ms. Simnick may be contacted at IAPMO, 909-472-4110 or email

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